Enter the "Options" menu. Select "Cheats", then "Enter New Cheat". Then, enter one of the following codes to unlock the corresponding cheat option. Note: Each note or chord must be strummed during code entry. Press Green at the "Cheats" menu to turn off a particular cheat.

Bat: Get a "Five Star" rank on all the songs under the Easy difficulty.
Nemesis 13: Complete Co-op Career mode under the Medium difficulty.
Moon Shot: Complete the game under the Easy difficulty.
Rojimbo: Complete the game under the Hard difficulty.
Saint George: Complete the game under the Medium difficulty.

Characters

Complete the indicated task to unlock the corresponding character.

Lou: Successfully complete the game to purchase Lou for $15,000. Lou comes with his skeleton guitar and two costumes (original devil outfit and werewolf viking).
MetalHead: Defeat it in the Boss battle in Career mode to unlock it for purchase at the store for $10,000.
Slash: Defeat him in the Boss battle in Career mode to unlock him for purchase at the store for $10,000.
Tom Morello: Defeat him in the Boss battle in Career mode to unlock him for purchase at the store for $10,000.

"Through The Fire And Flames" song

Defeat Lou to automatically unlock the "Through The Fire And Flames" song for free.

Achievements

Complete the following achievements to unlock Xbox Live Gamerscore points.

Enlightened Guitarist (30 points): Gold Star 20 songs on Expert.
Hendrix Reborn (10 points): Complete Career Lefty and Righty.
Who Needs the Power (15 points): 200k on Cult of Personality without Star Power.
Whammy Mania (15 points): Use the Whammy Bar on every held note on Number of the Beast.
Star Mania (15 points): Activate Star Power 3 times on Through the Fire and Flames on Expert.
Life of the Party (10 points): Host Ranked Online matches and win 15 consecutive songs.
Search and Destroy (10 points): Join Ranked Online matches and win 15 consecutive songs.
Too Many to Count (25 points): Hit 250,000 notes in Career.
Never Gonna Spend It All (10 points): Earn $350,000 in career lifetime earnings.
That's What Friends Are For (25 points): Complete Co-op Career.
Back Up Hero (10 points): Complete all songs as the back-up guitar player.
Guitar Wizard (10 points): Complete all Co-op as the lead guitarist.
100 Million!?! Gulp!?! (30 points): Earn 100,000,000 points total in Career.
Streaker (10 points): Earn a 150 note streak in a Ranked Online Battle mode match.
Tone Deaf (5 points): Beat any song on the expert difficulty with the games sound options turned down to zero.
Easy Rider (5 points): Complete a Career on the Easy Difficulty.
Medium Rare (10 points): Complete Career Mode on the Medium difficulty.
Always Hard (15 points): Complete Career on the Hard difficulty.
Solo Career (25 points): Complete all Career difficulties.
Button Masher (5 points): Win 15 consecutive Ranked songs online using a standard controller.
Buy a Guitar Already (15 points): Play through a career on the Hard or Expert difficulty using a standard controller.
Big 'Ol Pile of Wins (20 points): Win 500 Online Ranked matches.
The Long Road Ahead (100 points): Complete all difficulties in Career, buy everything from the shop and complete 100 online matches.
Meet Your Maker (20 points): Beat one of the creators of Guitar Hero 3 at their own game.
Right Hand of God (20 points): Complete Career Mode on the Expert difficulty.
Bronze Streaker (5 points): Earn a 100 note Streak in Career or Quick Play.
Silver Streaker (10 points): Earn a 250 note streak in Career or Quick Play.
Gold Streaker (15 points): Earn a 500 note streak in Career or Quick Play.
Streak Master (20 points): Earn a 1000 note streak in Career or Quick Play.
First Big Score (5 points): Score 250,000 on a song.
Half a Mill' (10 points): Score 500,000 on a song.
Now That's Impressive (20 points): Score 750,000 on a song.
Axe Grinder (10 points): Earn 5 stars on all songs on the Easy difficulty.
Rock Guru (20 points): Earn 5 stars on all songs on the Medium difficulty.
Shredder (30 points): Earn 5 stars on all songs on the Hard difficulty.
Guitar Hero (75 points): Earn 5 stars on all songs on the Expert difficulty.
Perfectionist (10 points): 100% a song.
Ready to Rock (5 points): Complete the tutorial.
Axe Collector (5 points): Buy all the Guitars from the shop.
Track Master (5 points): Buy all songs from the shop.
Got 'em All (5 points): Buy all characters from the shop.
A Couple of Streakers (5 points): Earn a 200 note streak in a Co-op match.
Two Timer (10 points): Earn a 500 note streak in a Co-op match.
Dynamic Duo (15 points): Earn a 1000 note streak in a Co-op match.
Streak Masters (20 points): Earn a 2000 note streak in a Co-op match.
Millionaire Club (20 points): Score 1,000,000 on any song in a Co-op match.
Higher Than Most (20 points): Score 700,000 on any song in a Co-op match.
Easy Duo (10 points): Earn 5 stars on all Co-op songs for the Easy difficulty.
Medium Duo (20 points): Earn 5 stars on all Co-op songs for the Medium difficulty.
Hard Duo (30 points): Earn 5 stars on all Co-op songs on the Hard difficulty.
Living Legends (75 points): 5 Star all Co-op songs on Expert.
Leaders of the Pack (10 points): 100% a song in a Co-op match.
Two by Four (5 points): Get an 8X multiplier in a Co-op game.
Half Mill' Club (10 points): Score 500,000 on any song in a Co-op match.
Burnin' a Hole in Your Pocket (10 points): Buy everything from the store.
The Inhuman Achievement (15 points): Complete Through the Fire and Flames on Expert.

if you cannot download trainer then go to Chrome/Firefox's settings, specifically to the Privacy settings and simply unchecking the "Enable phishing and malware protection" option.

Some Game Trainers are sometimes reported to be a Virus or Trojan,
the most common is a keylogger called HotKeysHook or the file
has been packed/protected with VMProtect or Themida and
is recognized as Win32/Packed.VMProtect or Win32/Packed.Themida.
In ALL cases this is a FALSE ALARM as NONE
of the Game Trainers @ GCW contain known malicious code! More info in
the PC
Games FAQ!